Posted by Brigham and Women's Hospital March 28, 2013

A recent study shows that vitamin D supplementation may help African-Americans lower their blood pressure.

There are a variety of things that you can do to help lower your blood pressure, such as exercise more, consume less salt, quit smoking, and eat low-fat foods. Now, African-Americans may be able to add “take more vitamin D” to that list.

High blood pressure is a major risk factor for heart attacks, heart failure, and stroke, and is 40 percent more common in African-Americans than in other American ethnic groups. Brigham and Women’s Hospital (BWH) recently collaborated with Dana-Farber Cancer Institute and Massachusetts General Hospital in a study that shows that vitamin D supplementation may help African-Americans lower their blood pressure. The study was published in the March 13, 2013, online edition of the American Heart Association journal Hypertension.

“This study may explain and help treat an important public health disparity,” says the study’s lead author, John Forman, MD, a physician in the Renal Division and Kidney Clinical Research Institute at BWH. “More research is needed, but these data may indicate that vitamin D supplementation lowers blood pressure in African-Americans.”

To conduct the study, 250 African-American adult volunteers were divided into four groups. Three of the groups received a three-month regimen of daily vitamin D supplementation at doses ranging between 1,000 and 4,000 units. The fourth group received a placebo. Participants in the placebo group saw their systolic blood pressure rise, but participants in the supplementation group had their systolic blood pressure decrease by one to four points, with those who received the highest dose benefiting the most. Systolic blood pressure, the top number in a blood pressure reading, measures the pressure in the arteries when the heart beats.

“The gains were modest, but significant,” said Forman. “If further research supports our finding, widespread use of vitamin D supplementation in African-Americans could have significant public health benefits.”